Melbourne, Jan 21 (DPA) Third seed Novak Djokovic booked easy passage into the fourth round of the Australian Open Friday as fellow Serb and Davis Cup teammate Viktor Troicki retired after losing their first set 6-2.
Djokovic, the 2008 champion, spent just 39 minutes on court before Troicki, who had withdrawn already from doubles with a stomach muscle strain, was unable to go on.
Djokovic and Troicki last played in the November Basel semi-finals. The Melbourne win was the seventh straight victory in the series for Djokovic.